Three-way valve for flow rate control and temperature control device using same

ABSTRACT

Provided are a three-way valve for flow rate control and a temperature control device using the three-way valve for flow rate control. The three-way valve for flow rate control is capable of controlling a mixture ratio between two kinds of fluids with higher accuracy, as compared to a three-way valve including an inflow port which allows inflow of a high-temperature heat-medium circulating liquid, an inflow port which allows inflow of a low-temperature heat-medium circulating liquid, an outflow port which allows outflow of a constant-temperature heat-medium circulating liquid, and a control valve configured to control the flow rate ratio between the high-temperature heat-medium circulating liquid and the low-temperature heat-medium circulating liquid. The three-way valve for flow rate control includes: a valve main body including a valve seat, the valve seat having a columnar space and having a first valve port, which allows inflow of a first fluid and has a rectangular cross section, and a second valve port, which allows inflow of a second fluid and has a rectangular cross section; a valve body being provided in a freely rotatable manner in the valve seat of the valve main body so as to simultaneously switch the first valve port from an closed state to an opened state and switch the second valve port from an opened state to a closed state, the valve body being formed into a half-cylindrical shape having a predetermined central angle and being formed into a curved-surface shape at each of both end surfaces of the valve body in a circumferential direction; and drive means for driving the valve body to rotate.

TECHNICAL FIELD

The present invention relates to a three-way valve for flow rate controland a temperature control device using the same.

BACKGROUND ART

Hitherto, as a technology relating to a three-way valve for flow ratecontrol, there has already been proposed, for example, a three-way valvefor flow rate control disclosed in Patent Literature 1.

In Patent Literature 1, provided is a constant-temperature maintainingdevice configured to control a temperature of an external heat loaddevice through indirect heat exchange with heat-medium circulatingliquid. The constant-temperature maintaining device includes a main unitand a sub unit. The main unit includes high-temperature heat-mediumcirculating-liquid generating means for generating a high-temperatureheat-medium circulating liquid adjusted to a predetermined temperature,and low-temperature heat-medium circulating-liquid generating means forgenerating a low-temperature heat-medium circulating liquid adjusted toa predetermined temperature. The sub unit includes constant-temperatureheat-medium circulating-liquid generating means for generating aheat-medium circulating liquid having a predetermined temperature bydirectly mixing the high-temperature heat-medium circulating liquid andthe low-temperature heat-medium circulating liquid and controlling aflow rate ratio between the high-temperature heat-medium circulatingliquid and the low-temperature heat-medium circulating liquid inaccordance with a temperature of the external heat load device.

Patent Literature 1 also encompasses the constant-temperatureheat-medium circulating-liquid generating means in a mode including athree-way valve, stirring-mixing-feeding means, and three-way-valvecontrol means. The three-way valve includes an inflow port which allowsinflow of the high-temperature heat-medium circulating liquid, an inflowport which allows inflow of the low-temperature heat-medium circulatingliquid, an outflow port which allows outflow of the constant-temperatureheat-medium circulating liquid, and a control valve configured tocontrol the flow rate ratio between the high-temperature heat-mediumcirculating liquid and the low-temperature heat-medium circulatingliquid. The stirring-mixing-feeding means is for stirring and mixing theconstant-temperature heat-medium circulating liquid to feed theconstant-temperature heat-medium circulating liquid. The three-way-valvecontrol means is for controlling an opening degree of the control valveof the three-way valve in accordance with a temperature of the externalheat load device.

CITATION LIST Patent Literature

[PTL 1] JP 2008-292026 A

SUMMARY OF INVENTION Technical Problem

The present invention provides a three-way valve for flow rate control,and a temperature control device using the three-way valve for flow ratecontrol. The three-way valve for flow rate control of the presentinvention is capable of controlling a mixture ratio between two kinds offluids with higher accuracy, as compared to the three-way valveincluding the inflow port which allows inflow of the high-temperatureheat-medium circulating liquid, the inflow port which allows inflow ofthe low-temperature heat-medium circulating liquid, the outflow portwhich allows outflow of the constant-temperature heat-medium circulatingliquid, and the control valve configured to control the flow rate ratiobetween the high-temperature heat-medium circulating liquid and thelow-temperature heat-medium circulating liquid.

Solution to Problem

According to the invention of claim 1, provided is a three-way valve forflow rate control, including:

a valve main body including a valve seat, the valve seat having acolumnar space and having a first valve port, which allows inflow of afirst fluid and has a rectangular cross section, and a second valveport, which allows inflow of a second fluid and has a rectangular crosssection;

a valve body being provided in a freely rotatable manner in the valveseat of the valve main body so as to simultaneously switch the firstvalve port from a closed state to an opened state and switch the secondvalve port from an opened state to a closed state, the valve body beingformed into a half-cylindrical shape having a predetermined centralangle and being formed into a curved-surface shape at each of both endsurfaces of the valve body in a circumferential direction; and

drive means for driving the valve body to rotate.

According to the invention of claim 2, in a three-way valve for flowrate control as described in claim 1, the valve body has the first valveport and the second valve port which are formed in an axial symmetricalmanner with respect to a rotation axis of the valve body as a centeraxis.

According to the invention of claim 3, in a three-way valve for flowrate control as described in claim 1 or 2, the valve body is formed of acylindrical body having a half-cylindrical portion, which is formed intoa half-cylindrical shape having a predetermined central angle by openingan outer peripheral surface of the cylindrical body, and having one endsurface in an axial direction being closed and another end surface beingopened.

According to the invention of claim 4, in a three-way valve for flowrate control as described in any one of claims 1 to 3, a cross sectionof each of both end portions of the valve body in the circumferentialdirection, which is taken along a direction intersecting the rotationaxis, is formed into an arc shape.

According to the invention of claim 5, in a three-way valve for flowrate control as described in any one of claims 1 to 3, a cross sectionof each of both end portions of the valve body in the circumferentialdirection, which is taken along a direction intersecting the rotationaxis, is formed into a curved shape obtained by smoothly connecting afirst curved portion, which is positioned on an outer peripheral surfaceside of the valve body, and a second curved portion, which is positionedon an inner peripheral side of the valve body and has a curvature radiussmaller than that of the first curved portion.

According to the invention of claim 6, provided is a temperature controldevice, including:

temperature control means having a flow passage for temperature controlwhich allows flow of a fluid for temperature control therethrough, thefluid for temperature control including a lower temperature fluid and ahigher temperature fluid adjusted in mixture ratio;

first supply means for supplying the lower temperature fluid adjusted toa first predetermined lower temperature;

second supply means for supplying the higher temperature fluid adjustedto a second predetermined higher temperature; and

a three-way valve connected to the first supply means and the secondsupply means, and configured to adjust the mixture ratio between thelower temperature fluid supplied from the first supply means and thehigher temperature fluid supplied from the second supply means and allowthe fluid for temperature control to flow through the flow passage fortemperature control,

in which the three-way valve for flow rate control as described in anyone of claims 1 to 5 is used as the three-way valve.

Advantageous Effects of Invention

According to the present invention, a three-way valve for flow ratecontrol and a temperature control device using the three-way valve forflow rate control can be provided. The three-way valve for flow ratecontrol of the present invention is capable of controlling a mixtureratio between two kinds of fluids with higher accuracy, as compared tothe three-way valve including the inflow port which allows inflow of thehigh-temperature heat-medium circulating liquid, the inflow port whichallows inflow of the low-temperature heat-medium circulating liquid, theoutflow port which allows outflow of the constant-temperatureheat-medium circulating liquid, and the control valve configured tocontrol the flow rate ratio between the high-temperature heat-mediumcirculating liquid and the low-temperature heat-medium circulatingliquid.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view for illustrating an outer appearance of athree-way motor valve as one example of a three-way valve for flow ratecontrol according to a first embodiment of the present invention.

FIG. 2(a) is a front view for illustrating the three-way motor valve asone example of the three-way valve for flow rate control according tothe first embodiment of the present invention.

FIG. 2(b) is a right side view of FIG. 2(a).

FIG. 2(c) is a bottom view of an actuator.

FIG. 3 is a sectional view taken along the line A-A of FIG. 2(b), forillustrating the three-way motor valve as one example of the three-wayvalve for flow rate control according to the first embodiment of thepresent invention.

FIG. 4 is a sectional perspective view for illustrating relevant partsof the three-way motor valve as one example of the three-way valve forflow rate control according to the first embodiment of the presentinvention.

FIG. 5 are sectional configuration views for illustrating a valveactuating portion.

FIG. 6 are configuration views for illustrating a valve shaft.

FIG. 7 are sectional configuration views for illustrating the valveactuating portion.

FIG. 8 is a graph for showing characteristics of the three-way motorvalve as one example of the three-way valve for flow rate controlaccording to the first embodiment of the present invention.

FIG. 9 is a graph for showing the characteristics of the three-way motorvalve as one example of the three-way valve for flow rate controlaccording to the first embodiment of the present invention.

FIG. 10 is a schematic diagram for illustrating a constant-temperaturemaintaining device (chiller device) to which the three-way motor valveas one example of the three-way valve for flow rate control according tothe first embodiment of the present invention is applied.

FIG. 11 are sectional configuration views for illustrating another valveactuating portion.

DESCRIPTION OF EMBODIMENTS

In the following, embodiments of the present invention are describedwith reference to the drawings.

First Embodiment

FIG. 1 is a perspective view for illustrating an outer appearance of athree-way motor valve as one example of a three-way valve for flow ratecontrol according to a first embodiment of the present invention. FIG.2(a) is a front view. FIG. 2(b) is a right side view of FIG. 2(a). FIG.2(c) is a bottom view of an actuator. FIG. 3 is a sectional view takenalong the line A-A of FIG. 2(b). FIG. 4 is a vertical sectionalperspective view for illustrating relevant parts of the three-way motorvalve.

A three-way motor valve 1 is constructed as a rotary three-way valve. Asillustrated in FIG. 1, the three-way motor valve 1 mainly includes avalve portion 2 arranged at a lower portion thereof, an actuator 3arrange at an upper portion thereof, and a sealing portion 4 and acoupling portion 5, which are arranged between the valve portion 2 andthe actuator 3.

As illustrated in FIG. 2 to FIG. 4, the valve portion 2 includes a valvemain body 6 obtained by forming metal, for example, SUS, into asubstantially rectangular parallelepiped shape. As illustrated in FIG.3, a first inflow port 7 and a first valve port 9 are opened in one sidesurface (left side surface in the illustrated example) of the valve mainbody 6. The first inlet port 7 allows inflow of a lower temperaturefluid as a first fluid. The first valve port 9 has a rectangular crosssection, and communicates with a valve seat 8 having a columnar space. Afirst flange member 10 for connecting a pipe (not shown) which allowsinflow of the lower temperature fluid is mounted to the left sidesurface of the valve main body 6 with four hexagon socket head capscrews 11. Similarly to the valve main body 6, the first flange member10 is formed of metal, for example, SUS. The first flange member 10 hasa flange portion 12, an insertion portion 13, and a pipe connectingportion 14. The flange portion 12 has a side surface formed into thesame rectangular shape as the side surface of the valve main body 6. Theinsertion portion 13 is provided to protrude from an inner surface ofthe flange portion 12 so as to have a thin cylindrical shape. The pipeconnecting portion 14 is provided to protrude from an outer surface ofthe flange portion 12 so as to have a thick and substantiallycylindrical shape. A pipe (not shown) is connected to the pipeconnecting portion 14. An inner periphery of the pipe connecting portion14 is set to, for example, Rc ½ being a standard for a tapered femalethread having a bore diameter of around 21 mm. An inner peripheral endon an outer side of the first inlet port 7 of the valve main body 6 hasa chamfer 16 to allow an O-ring 15 to be mounted between the first inletport 7 of the valve main body 6 and the flange portion 12 of the firstflange member 10.

A second inflow port 17 and a second valve port 18 are opened in anotherside surface (right side surface in the illustrated example) of thevalve main body 6. The second inflow port 17 allows inflow of a highertemperature fluid as a second fluid. The second valve port 18 has arectangular cross section, and communicates with the valve seat 8 havingthe columnar space. A second flange member 19 for connecting a pipe (notshown) which allows inflow of the higher temperature fluid is mounted tothe right side surface of the valve main body 6 with four hexagon sockethead cap screws 20. Similarly to the first flange member 10, the secondflange member 19 is formed of metal, for example, SUS. The second flangemember 19 has a flange portion 21, an insertion portion 22, and a pipeconnecting portion 23. The flange portion 21 has a side surface formedinto the same rectangular shape as the side surface of the valve mainbody 6. The insertion portion 22 is provided to protrude from an innersurface of the flange portion 21 so as to have a thin cylindrical shape.The pipe connecting portion 23 is provided to protrude from an outersurface of the flange portion 21 so as to have a thick and substantiallycylindrical shape. A pipe (not shown) is connected to the pipeconnecting portion 23. An inner periphery of the pipe connecting portion23 is set to, for example, Rc ½ being a standard for a tapered femalethread having a bore diameter of around 21 mm. An inner peripheral endon an outer side of the second inflow port 17 of the valve main body 6has a chamfer 25 to allow an O-ring 24 to be mounted between the secondinflow port 17 of the valve main body 6 and the flange portion 21 of thesecond flange member 19.

Here, the lower temperature fluid as the first fluid and the highertemperature fluid as the second fluid are fluids to be used fortemperature control. A fluid having a relatively lower temperature isreferred to as “lower temperature fluid,” and a fluid having arelatively higher temperature is referred to as “higher temperaturefluid.” Thus, the lower temperature fluid and the higher temperaturefluid have a relative relationship. The lower temperature fluid is not afluid having an absolutely low temperature, and the higher temperaturefluid is not a fluid having an absolutely high temperature. As the lowertemperature fluid and the higher temperature fluid, for example, underair pressure of from 0 MPa to 1 MPa and within a temperature range offrom about 0° C. to about 80° C., water (such as pure water) adjusted toa temperature of from about 0° C. to about 30° C. and water (pure water)adjusted to a temperature of from about 50° C. to about 80° C. aresuitably used, respectively. Further, as the lower temperature fluid andthe higher temperature fluid, for example, within a temperature range offrom about −20° C. to about +80° C., there is used a fluid such afluorine-based inert liquid, for example, Fluorinert (trademark) andethylene glycol, which are neither frozen at a temperature of about −20°C. nor vaporized at a temperature of about +80° C.

Further, in a lower end surface of the valve main body 6, an outflowport 26 is opened. The outflow port 26 allows outflow of a fluid fortemperature control, which is a mixture of the lower temperature fluidand the higher temperature fluid. A third flange member 27 forconnecting a pipe (not shown) which allows outflow of the fluid fortemperature control is mounted to the lower end surface of the valvemain body 6 with four hexagon socket head cap screws 28. Similarly tothe first and second flange members 10 and 19, the third flange member27 is formed of metal, for example, SUS. The third flange member 27 hasa flange portion 29, an insertion portion 30, and a pipe connectingportion 31. The flange portion 29 has a planar surface formed into arectangular shape, which is smaller than the lower end surface of thevalve main body 6. The insertion portion 30 is provided to protrude froman upper end surface of the flange portion 29 so as to have a thincylindrical shape. The pipe connecting portion 31 is provided toprotrude from a lower end surface of the flange portion 29 so as to havea thick and substantially cylindrical shape. A pipe (not shown) isconnected to the pipe connecting portion 31. An inner periphery of thepipe connecting portion 31 is set to, for example, Rc ½ being a standardfor a tapered female thread having a bore diameter of around 21 mm. Aninner peripheral end on a lower end of the third inflow port 26 of thevalve main body 6 is has a chamfer 33 to allow an O-ring 32 to bemounted between the third outflow port 26 of the valve main body 6 andthe flange portion 29 of the third flange member 27.

The valve main body 6 includes, in a center thereof, the valve seat 8having a second valve port 18. The second valve port 18 has a crosssection formed into the same rectangular shape as that of the firstvalve port 9. The valve seat 8 has a space formed into a columnar shapecorresponding to an outer shape of a valve body to be described later.The valve seat 8 formed into a columnar shape is provided in a state ofpenetrating an upper end surface of the valve main body 6. Asillustrated in FIG. 5, the first valve port 9 and the second valve port18 provided to the valve main body 6 are arranged in an axialsymmetrical manner with respect to a center axis (rotation axis) C ofthe valve seat 8 formed into a columnar shape. More specifically, thefirst valve port 9 and the second valve port 18 are arranged so as to beorthogonal with respect to the valve seat 8 formed into a columnarshape. One end edge of the first valve port 9 is opened in a positionopposed to another end edge of the second valve port 18 through thecenter axis C, that is, in a position different by 180°. Further,another end edge of the first valve port 9 is opened in a positionopposed to one end edge of the second valve port 18 through the centeraxis C, that is, in a position different by 180°.

Further, as illustrated in FIG. 4, the first valve port 9 and the secondvalve port 18 are each formed of an opening having a cross sectionformed into a rectangular shape, for example, a square shape. A lengthof one side of the first valve port 9 and the second valve port 18 isset to be smaller than a diameter of the first inlet port 7 and thesecond inflow port 17. The first valve port 9 and the second valve port18 have a cross section formed into a rectangular shape inscribed in thefirst inlet port 7 and the second inflow port 17.

As illustrated in FIG. 6, a valve shaft 34 as one example of the valvebody has an outer shape obtained by forming metal, for example, SUS,into a substantially columnar shape. The valve shaft 34 mainly includesa valve body portion 35, upper and lower shaft support parts 36 and 37,a sealing portion 38, and a coupling portion 40, which are integrallyprovided. The valve body portion 35 functions as a valve body. The upperand lower shaft support parts 36 and 37 are provided above and below thevalve body portion 35, respectively, and support the valve shaft 34 in afreely rotatable manner. The sealing portion 38 is provided to an upperportion of the upper shaft support portion 36. The coupling portion 40is provided to an upper portion of the sealing portion 38 throughintermediation of a tapered portion 39.

The upper and lower shaft support parts 36 and 37 are formed into acylindrical shape so as to have an outer diameter smaller than that ofthe valve body portion 35 and so as to have an equal diameter. A lengthof the lower shaft support portion 37 in an axial direction is set to beslightly larger than that of the upper shaft support portion 36. Asillustrated in FIG. 3, the lower shaft support portion 37 is supportedin a freely rotatable manner through intermediation of a bearing 41 by alower end of the valve seat 8 provided to the valve main body 6. Anannular support portion 42 supporting the bearing 41 is provided at alower portion of the valve seat 8 so as to protrude toward an innerperiphery. The bearing 41, the support portion 42, and the insertionportion 30 of the third flange member 27 are set to have an equal innerdiameter, and are configured to allow outflow of the fluid fortemperature control, which has passed through an inside of the valvebody portion 35, to the connecting portion of the third flange member 27with little resistance. Meanwhile, a thrust washer 43 is mounted to theupper shaft support portion 36 to reduce a load generated by the valveshaft 34 pressed by a sealing case 53 to be described later.

Further, as illustrated in FIG. 5 and FIG. 6, the valve body portion 35is formed into a cylindrical shape having an opening formed therein. Theopening 44 has a substantially half-cylindrical shape with an openingheight H2, which is smaller than an opening height H1 (see FIG. 3) ofthe first and second valve ports 9 and 18. A valve operating portion 45having the opening 44 of the valve body portion 35 is formed into ahalf-cylindrical shape (substantially half-cylindrical shape of acylindrical portion excluding the opening 44) having a predeterminedcentral angle α (for example, about 190°). The valve operating portion45 is arranged in a freely rotatable manner in the valve seat 8 and heldin contact with an inner peripheral surface of the valve seat 8.Accordingly, with the valve body portion 35 positioned above and belowthe opening 44 included, the valve operating portion 45 simultaneouslyswitches the first valve port 9 from a closed state to an opened stateand the second valve port 18 from an opened state to a closed state in areverse direction. As illustrated in FIG. 6, upper and lower valve shaftparts 46 and 47 arranged above and below the valve operating portion 45are formed into a cylindrical shape having an outer diameter equal tothat of the valve operating portion 45, and are held in contact with theinner peripheral surface of the valve seat 8 in a freely rotatablemanner. In an inside over the valve operating portion 45, the upper andlower valve shaft parts 46 and 47, and the sealing portion 38, a space48 is provide in a state of penetrating the valve shaft 34 toward alower edge thereof. The space 48 has a columnar shape having a diameterreduced in size toward an upper end thereof.

Further, a cross section of each of both end surfaces 45 a and 45 b ofthe valve operating portion 45 in a circumferential direction (rotationdirection), which is taken along a direction intersecting (orthogonalto) the center axis C, is formed into a curved-surface shape. Morespecifically, as illustrated in FIG. 5, the cross section of each of theboth end portions 45 a and 45 b of the valve operating portion 45 in thecircumferential direction, which is taken along a direction intersectingthe rotation axis C, is formed into an arc shape being convex toward theopening 44. A curvature radius of each of the both end portions 45 a and45 b is set to, for example, a half of a thickness T of the valveoperating portion 45. As a result, a cross section of each of the bothend portions 45 a and 45 b is a semicircular shape.

The cross section of each of the both end portions 45 a and 45 b of thevalve operating portion 45 in the circumferential direction, which istaken along a direction intersecting the rotation axis C, is not limitedto an arc shape. It is only necessary that each of the both end surfaces45 a and 45 b in the circumferential direction (rotation direction) beformed into a curved-surface shape. As illustrated in FIG. 5(b), thecross section of each of the both end portions 45 a and 45 b of thevalve operating portion 45 in the circumferential direction, which istaken along a direction intersecting the rotation axis C, maybe formedinto a curved shape obtained by smoothly connecting a first curvedportion 50, which is positioned on an outer peripheral side, and asecond curved portion 51, which is positioned on an inner peripheralside and has a curvature radius smaller than that of the first curvedportion 50.

As illustrated in FIG. 5, when the valve shaft 34 is driven to rotate toopen and close the first and second valve ports 9 and 18, in flows ofthe lower temperature fluid and the higher temperature fluid, the bothend portions 45 a and 45 b of the valve operating part 45 in thecircumferential direction are moved (rotated) so as to protrude from orretreat to the ends of the first and second valve ports 9 and 18 in thecircumferential direction. Accordingly, the first and second valve ports9 and 18 are switched from the opened state to the closed state, or fromthe closed state to the opened state. At this moment, each of the bothend portions 45 a and 45 b of the valve operating portion 45 in thecircumferential direction have a cross section formed into acurved-surface shape so as to linearly change opening areas of the firstand second valve ports 9 and 18 with respect to a rotation angle of thevalve shaft 34.

More specifically, as illustrated in FIG. 11, in a case where the bothend portions 45 a and 45 b of the valve operating portion 45 in thecircumferential direction are formed into a planar shape along a radialdirection, when an opening degree of the valve shaft 34 exceeds 50%, aninner peripheral end of the valve operating portion 45 protrudes more ina direction of causing opening widths of the first and second valveports 9 and 18 to be reduced as compared to an outer peripheral end ofthe valve operating portion 45. Accordingly, the opening areas of thefirst and second valve ports 9 and 18 with respect to the rotation angleof the valve shaft 34 cannot be linearly changed.

On the contrary, as illustrated in FIG. 7(b), in a case where the crosssection of each of the both end portions 45 a and 45 b of the valveoperating portion 45 in the circumferential direction is formed into acurved-surface shape, even when the opening degree of the valve shaft 34exceeds 50%, the opening areas of the first and second valve ports 9 and18 with respect to the rotation angle of the valve shaft 34 can belinearly changed.

Thus, the both end portions 45 a and 45 b of the valve operating portion45 in the circumferential direction are assumed to bring about effectsas blade bodies protruding toward the flows of the fluids flowing intothe valve chamber 8 through the first and second valve ports 9 and 18.Therefore, the both end portions 45 a and 45 b of the valve operatingportion 45 in the circumferential direction, which bring about theeffects as the blade bodies protruding toward the flows, play animportant role in controlling the flow rate of the fluids by limiting orreleasing the flows of the fluids. Depending on the flows of the fluidsin a periphery of the both end portions 45 a and 45 b of the valveoperating portion 45 in the circumferential direction, which protrudetoward the fluids, in a case where the opening areas of the first andsecond valve ports 9 and 18 are linearly changed by the valve operatingportion 45 of the valve shaft 34, the flow rate of the lower temperaturefluid and the higher temperature fluid, which are to flow in and to bemixed in the valve chamber 8, is not necessarily changed linearly.

Through various studies that have been conducted by the inventors of thepresent invention, it has been revealed that the cross section of theboth end portions 45 a and 45 b of the valve operating portion 45 in thecircumferential direction plays an important role in linearlycontrolling the flow rate of the lower temperature fluid and the highertemperature fluid, which are to be mixed in the valve chamber 8.Further, the inventors of the present invention have found out that theflow rate of the lower temperature fluid and the higher temperaturefluid can be linearly controlled by forming the cross section of theboth end portions 45 a and 45 b of the valve operating portion 45 in thecircumferential direction into a curved-surface shape.

As illustrated in FIG. 3, the sealing portion 4 is configured to sealthe valve shaft 34 in a liquid-tight state. The sealing portion 4 hasthe sealing case 53 obtained by forming metal, for example, SUS, into acylindrical shape. The sealing case 53 has an insertion through hole 52through which the valve shaft 34 is inserted. The sealing case 53 isinserted and fixed in a concave portion 54, which is provided to anupper end surface of the valve main body 6 and has a columnar shape,under a state in which a sealing agent is applied to the sealing case 53or mounted to the valve main body 6 in a sealed state through means suchas screw fastening to the concave portion 54 with a male thread portion(not shown) provided to an outer periphery of the sealing case 53. In aninner peripheral surface of the sealing case 53, two annular sealingmembers 55 and 56, which are formed of O-rings or the like for sealingthe valve shaft 34, are arranged in a vertical direction. As the sealingmembers 55 and 56, for example, an O-ring made of hydrogenatedacrylonitrile-butadiene rubber (H-NBR), which is excellent in heatresistance, oil resistance, and weather resistance, is used. The sealingcase 53 is positioned by a parallel pin 57 and mounted to the concaveportion 54 of the valve main body 6.

The coupling portion 5 is arranged between the valve main body 6, inwhich the sealing portion 4 is provided, and the actuator 3. Thecoupling portion 5 is configured to connect the valve shaft 34 and arotation shaft 58, which allows the valve shaft 34 to be integrallyrotated, to each other. The coupling portion 5 includes a spacer member59, an adaptor plate 60, and a coupling member 62. The spacer member 59is arranged between the sealing portion 4 and the actuator 3. Theadaptor plate 60 is fixed to an upper portion of the spacer member 59.The coupling member 62 is accommodated in a space 61 having a columnarshape formed in a state of penetrating an inside of the spacer member 59and the adaptor plate 60, and connects the valve shaft 34 and therotation shaft 58 to each other. The spacer member 59 is obtained byforming metal, for example, SUS, into a parallelepiped shape, which hassubstantially the same planar shape as that of the valve main body 6 anda relatively small height. The spacer member 59 is fixed to both thevalve main body 6 and the adaptor plate 60 through means such as screwfastening. Further, as illustrated in FIG. 2(c), the adaptor plate 60 isobtained by forming metal, for example, SUS, into a plate-like shapehaving a planar polygonal shape. The adaptor plate 60 is mounted to thebase 64 of the actuator 3 in a fixed state with hexagon socket head capscrews 63.

As illustrated in FIG. 3, the coupling member 62 is obtained by formingmetal, a synthetic resin having heat resistance, or the like into acylindrical shape. A concave groove 65 is formed so as to penetrate anupper end of the valve shaft 34 in a horizontal direction. Further, thevalve shaft 34 is coupled and fixed to the coupling member 62 throughthe concave groove 65 with a connecting pin 66 provided so as topenetrate the coupling member 62. Meanwhile, a lower end portion of therotation shaft 58 is coupled and fixed to the coupling member 62 with aconnecting pin 67 provided so as to penetrate the coupling member 62.The spacer member 59 has an opening 68 formed in a side surface thereoffor detecting leakage of a liquid through the insertion through hole 52when the liquid leaks from the sealing members 55 and 56. The opening 68is set to, for example, Rc 1/16 being a standard for a tapered femalethread having a bore diameter of around 8 mm.

As illustrated in FIG. 2, the actuator 3 includes the base 64 having aplanar surface formed into a rectangular shape. A casing 70 is mountedto an upper portion of the base 64 with screws 71. The casing 70 isconstructed as a box body having a rectangular parallelepiped shape,which contains drive means including a stepping motor, an encoder, andthe like. The drive means in the actuator 3 only needs to be capable ofrotating the rotation shaft 58 in a desired direction with predeterminedaccuracy based on control signals, and configuration thereof is notlimited. The drive means includes a stepping motor, a driving forcetransmission mechanism, and an angle sensor. The driving forcetransmission mechanism is configured to transmit a rotational drivingforce of the stepping motor to the rotation shaft 58 throughintermediation of driving force transmission means, for example, a gear.The angle sensor is, for example, an encoder or the like configured todetect a rotation angle of the rotation shaft 58.

In FIG. 2, a reference symbol 72 denotes a stepping motor-side cable,and a reference symbol 73 denotes an angle sensor-side cable. Thestepping motor-side cable 72 and the angle sensor-side cable 73 areconnected to a control device (not shown) configured to control thethree-way motor valve 1.

<Operation of Three-way Motor Valve>

In the three-way motor valve 1 according to the embodiment of thepresent invention, the flow rate of the lower temperature fluid and thehigher temperature fluid is controlled as follows.

As illustrated in FIG. 1, through the first flange member 10 and thesecond flange member 19, the lower temperature fluid adjusted to apredetermined lower temperature and the higher temperature fluidadjusted to a predetermined higher temperature are supplied throughpipes (not shown) to the three-way motor valve 1. As illustrated in FIG.7(a), for example, in an initial state before start of operation, thethree-way motor valve 1 is brought into a state in which the valveoperating portion 45 of the valve shaft 34 simultaneously closes(completely closes) the first valve port 9 and opens (completely opens)the second valve port 18.

As illustrated in FIG. 3, in the three-way motor valve 1, when thestepping motor (not shown) provided in the actuator 3 is driven torotate by a predetermined amount, the rotation shaft 58 is driven torotate in accordance with a rotation amount of the stepping motor. Inthe three-way motor valve 1, when the rotation shaft 58 is driven torotate, the valve shaft 34 coupled and fixed to the rotation shaft 58 isrotated by an angle equivalent to the rotation amount (rotation angle)of the rotation shaft 58. The valve operating portion 45 is rotated inthe valve seat 8 along with the rotation of the valve shaft 34. Withthis, as illustrated in FIG. 5(a), the one end portion 45 a of the valveoperating portion 45 in the circumferential direction gradually opensthe first valve port 9. As a result, the lower temperature fluid flowingin from the first housing member 10 through the first inlet port 7 flowsinto the valve seat 8 through the first valve port 9.

At this moment, as illustrated in FIG. 5(a), the another end portion 45b of the valve operating portion 45 in the circumferential directionopens the second valve port 18. Accordingly, the higher temperaturefluid flowing in from the second housing member 19 through the secondinflow port 17 flows into the valve seat 8 through the second valve port18. Then, the higher temperature fluid mixed with the lower temperaturefluid flows out from the third housing member 27 via the valve seat 8through the outflow port 30 of the valve main body 6. A temperature ofthe higher temperature fluid is adjusted to a constant temperature (forexample, 80° C.), which is higher than a temperature of the lowertemperature fluid and is determined in advance.

As illustrated in FIG. 7(b), in the three-way motor valve 1, when thevalve shaft 34 is driven to rotate, and the one end portion 45 a of thevalve operating portion 45 in the circumferential direction graduallyopens the first valve port 9, the lower temperature fluid flowing inthrough the first housing member 10 and the higher temperature fluidflowing in through the second housing member 19 are mixed in the valvechamber 8 and the valve shaft 34, with the result that the fluid fortemperature control is obtained. The fluid for temperature control issupplied to the outside from the third housing member 27 through theoutflow port 30 of the valve main body 6.

In the three-way motor valve 1, the valve shaft 34 is rotated as therotation shaft 58 is driven to rotate. The one end portion 45 a of thevalve operating portion 45 in the circumferential direction graduallyopens the first valve port 9, and at the same time, the another endportion 45 b of the valve operating portion 45 in the circumferentialdirection gradually closes the second valve port 18. The lowertemperature fluid flowing in through the first valve port 9 and thehigher temperature fluid flowing in through the second valve port 18 aremixed in the valve chamber 8 and the valve shaft 34. Then, the resultingfluid for temperature control, which is adjusted in temperature inaccordance with a mixture ratio between the lower temperature fluid andthe higher temperature fluid, is supplied to the outside through theoutflow port 30 of the valve main body 6.

Further, in the three-way motor valve 1, each of the both end portions45 a and 45 b of the valve operating portion 45 in the circumferentialdirection has a cross section formed into a curved-surface shape. Thus,the opening areas of the first and second valve ports 9 and 18 can belinearly changed with respect to the rotation angle of the valve shaft34. Further, it is conceivable that the lower temperature fluid and thehigher temperature fluid regulated in flow rate by the both end portions45 a and 45 b of the valve operating portion 45 flow in a form of anearly laminar flow. Therefore, the mixture ratio (flow rate) betweenthe lower temperature fluid and the higher temperature fluid can becontrolled with high accuracy in accordance with the opening areas ofthe first valve port 9 and the second valve port 18.

Example of Experiment

The inventors of the present invention experimentally produced thethree-way motor valves 1 respectively including the valve shafts 34 asillustrated in FIG. 5(a) and FIG. 5(b), and carried out an experiment tocheck how a flow coefficient Cv value of each of the lower temperaturefluid and the higher temperature fluid changes in accordance withopening degrees of the first valve port 9 and the second valve port 18along with the rotation of the valve shaft 34.

The flow coefficient Cv value of each of the lower temperature fluid,the higher temperature fluid, and the fluid for temperature control,which is a mixture of the lower temperature fluid and the highertemperature fluid, were measured by moving one flow rate sensor havinghigh detection accuracy to each of the first valve port 9, the secondvalve port 18, and the outflow port 30 individually at the timing whenthe rotation angle of the valve shaft 34 was changed.

FIG. 8 and FIG. 9 are graphs for showing results of the above-mentionedexamples. FIG. 8 corresponds to the valve shaft of FIG. 5(a), and FIG. 9corresponds to the valve shaft of FIG. 5(b).

As a result, as is apparent from the graphs shown in FIG. 8 and FIG. 9,the flow coefficient Cv value of the lower temperature fluid waslinearly increased along with the rotation angle of the valve shaft 34.Simultaneously, the flow coefficient Cv value of the higher temperaturefluid was linearly reduced. It has been revealed that the mixture ratio(flow rate) between the lower temperature fluid and the highertemperature fluid can be controlled with high accuracy. Further, as isapparent from the graphs shown in FIG. 8 and FIG. 9, in a region wherethe opening degree of the valve shaft 34 was 50% or more, the valveshafts of FIG. 5(a) and FIG. 5(b) each had a region where the flowcoefficient Cv value was slightly deviated from the linear line. Thereason for this is assumed to be derived from the curved-surface shapeof each of the both end portions 45 a and 45 b because, in the case ofthe valve shaft of FIG. 5(b), the region where the flow coefficient Cvvalue was slightly deviated from the linear line was shifted to theregion where the opening degree of the valve shaft 34 was higher ascompared to the case of the valve shaft of FIG. 5(a).

In the graph shown in FIG. 9, even when the valve shaft 34 was rotatedto a completely opened position, it can be seen that the flowcoefficient Cv value of one fluid did not become completely zero. Thisis probably because the curvature radius of the outer peripheral side ofeach of the both end portions 45 a and 45 b of the valve operatingportion 45 in the circumferential direction was set larger. However, inconsideration that the three-way motor valve 1 is used for temperaturecontrol, even when the flow coefficient Cv value of the one fluid doesnot become completely zero in the case where the valve shaft 34 isrotated to the completely opened position, there arises no problem inactual use when other open/close valves are used in combination.

EXAMPLE 1

FIG. 10 is a schematic diagram for illustrating a constant-temperaturemaintaining device (chiller device) to which the three-way motor valveas one example of the three-way valve for flow rate control according tothe first embodiment of the present invention is applied.

A chiller device 100 is, for example, used for a semiconductormanufacturing apparatus involving plasma etching, and configured tomaintain a temperature of a semiconductor wafer or the like as oneexample of a temperature control target W to a constant temperature. Thetemperature control target W, for example, a semiconductor wafer, mayrise in temperature along with generation or discharge of plasma or thelike after being subjected to plasma etching or the like.

The chiller device 100 includes a temperature control portion 101constructed to have a table-like shape as one example of the temperaturecontrol means arranged so as to be held in contact with the temperaturecontrol target W. The temperature control portion 101 has a flow passage102 for temperature control therein. The fluid for temperature control,which includes the lower temperature fluid and the higher temperaturefluid having been adjusted in mixture ratio, flows through the flowpassage 102 for temperature control.

The three-way motor valve 1 is connected to the flow passage 102 fortemperature control in the temperature control portion 101 through anopen/close valve 103. A constant-temperature reservoir 104 for lowertemperature is connected to the first flange portion 10 of the three-waymotor valve 1. The constant-temperature reservoir 104 for lowertemperature stores the low temperature fluid adjusted to a predeterminedlower temperature. The lower temperature fluid is supplied to thethree-way motor valve 1 from the constant-temperature reservoir 104 forlower temperature by a first pump 105. Further, a constant-temperaturereservoir 106 for higher temperature is connected to the second flangeportion 19 of the three-way motor valve 1. The constant-temperaturereservoir 106 for higher temperature stores the high temperature fluidadjusted to a predetermined higher temperature. The higher temperaturefluid is supplied to the three-way motor valve 1 from theconstant-temperature reservoir 106 for higher temperature by a secondpump 107. The third flange member 27 of the three-way motor valve 1 isconnected to the flow passage 102 for temperature control in thetemperature control portion 101 through the open/close valve 103.

Further, on an outflow side of the flow passage 102 for temperaturecontrol in the temperature control portion 101, a pipe for returning isprovided. The pipe for returning is connected to theconstant-temperature reservoir 104 for lower temperature and theconstant-temperature reservoir 106 for higher temperature.

The three-way motor valve 1 includes a stepping motor 108 configured todrive the valve shaft 34 to rotate. Further, a temperature sensor 109configured to detect a temperature of the temperature control portion101 is provided to the temperature control portion 101. The temperaturesensor 109 is connected to a control device (not shown), and the controldevice is configured to control a drive of the stepping motor 108 of thethree-way motor valve 1.

As illustrated in FIG. 10, in the chiller device 100, a temperature ofthe temperature control target W is detected by the temperature sensor109. Based on a detection result obtained by the temperature sensor 109,the rotation of the stepping motor 108 of the three-way motor valve 1 iscontrolled by the control device. Accordingly, the temperature controltarget W is controlled to a temperature equal to a predeterminedtemperature.

When the valve shaft 34 is driven to rotate by the stepping motor 108,the three-way motor valve 1 controls the mixture ratio between the lowertemperature fluid, which is supplied from the constant-temperaturereservoir 104 for lower temperature by the first pump 105, and thehigher temperature fluid, which is supplied from theconstant-temperature reservoir 106 for higher temperature by the secondpump 107, to control a temperature of the fluid for temperature control,which is a mixture of the lower temperature fluid and the highertemperature fluid to be supplied to the flow passage 102 for temperaturecontrol in the temperature control portion 101 from the three-way motorvalve 1 through the open/close valve 103.

At this moment, as illustrated in FIG. 8, the three-way motor valve 1 iscapable of controlling the mixture ratio between the lower temperaturefluid and the higher temperature fluid in accordance with the rotationangle of the valve shaft 34 with high accuracy, thereby being capable offinely adjusting a temperature of the fluid for temperature control.Thus, the chiller device 100 using the three-way motor valve 1 accordingto the embodiment of the present invention is capable of controlling atemperature of the temperature control target W, which is held incontact with the temperature control portion 101, to a desiredtemperature, by allowing the fluid for temperature control, which iscontrolled in mixture ratio between the lower temperature fluid and thehigher temperature fluid and adjusted in temperature to a predeterminedtemperature, to flow through the flow passage 102 for temperaturecontrol in the temperature control portion 101.

INDUSTRIAL APPLICABILITY

The three-way valve for flow rate control is capable of controlling themixture ratio between the two kinds of fluids with high accuracy.Through use of the three-way valve for flow rate control in thetemperature control device, a temperature of the temperature controltarget can be controlled with high accuracy.

REFERENCE SIGNS LIST

1 three-way motor valve

-   2 valve portion-   3 actuator-   4 sealing portion-   5 coupling portion-   6 valve main body-   7 first inflow port-   8 valve seat-   9 first valve port-   10 first flange member-   11 hexagon socket head cap screw-   12 flange portion-   13 insertion portion-   14 pipe connecting portion-   15 O-ring-   16 chamfer-   17 second inflow port-   18 second valve port-   19 second flange member-   20 hexagon socket head cap screw-   21 flange portion-   22 insertion portion-   23 pipe connecting portion-   34 valve shaft-   35 valve body portion-   45 valve operating portion-   45 a, 45 b end portion

1. A three-way valve for flow rate control, comprising: a valve mainbody including a valve seat, the valve seat having a columnar space andhaving a first valve port, which allows inflow of a first fluid and hasa rectangular cross section, and a second valve port, which allowsinflow of a second fluid and has a rectangular cross section; a valvebody being provided in a freely rotatable manner in the valve seat ofthe valve main body so as to simultaneously switch the first valve portfrom an closed state to an opened state and switch the second valve portfrom an opened state to a closed state, the valve body being formed intoa half-cylindrical shape having a predetermined central angle and beingformed into a curved-surface shape at each of both end surfaces of thevalve body in a circumferential direction; and drive means configured todrive the valve body to rotate.
 2. A three-way valve for flow ratecontrol according to claim 1, wherein the valve body has the first valveport and the second valve port which are formed in an axial symmetricalmanner with respect to a rotation axis of the valve body as a centeraxis.
 3. A three-way valve for flow rate control according to claim 1 or2, wherein the valve body is formed of a cylindrical body having ahalf-cylindrical portion, which is formed into a half-cylindrical shapehaving a predetermined central angle by opening an outer peripheralsurface of a cylindrical body, and having one end surface thereof in anaxial direction being closed and another end surface being opened.
 4. Athree-way valve for flow rate control according to claim 1, wherein across section of each of both end portions of the valve body in thecircumferential direction, which is taken along a direction intersectingthe rotation axis, is formed into an arc shape.
 5. A three-way valve forflow rate control according to claim 1, wherein a cross section of eachof both end portions of the valve body in the circumferential direction,which is taken along a direction intersecting the rotation axis, isformed into a curved shape obtained by smoothly connecting a firstcurved portion, which is positioned on an outer peripheral surface sideof the valve body, and a second curved portion, which is positioned onan inner peripheral side of the valve body and has a curvature radiussmaller than that of the first curved portion.
 6. A temperature controldevice, comprising: temperature control means having a flow passage fortemperature control which allows flow of a fluid for temperature controltherethrough, the fluid for temperature control including a lowertemperature fluid and a higher temperature fluid adjusted in mixtureratio; first supply means for supplying the lower temperature fluidadjusted to a first predetermined lower temperature; second supply meansfor supplying the higher temperature fluid adjusted to a secondpredetermined higher temperature; and a three-way valve connected to thefirst supply means and the second supply means, and configured to adjustthe mixture ratio between the lower temperature fluid supplied from thefirst supply means and the higher temperature fluid supplied from thesecond supply means and allow the fluid for temperature control to flowthrough the flow passage for temperature control, wherein the three-wayvalve for flow rate control of claim 1 is used as the three-way valve.7. A three-way valve for flow rate control, comprising: a valve mainbody including a valve seat, the valve seat having a columnar space andhaving a first valve port, which allows inflow of a first fluid and hasa rectangular cross section, and a second valve port, which allowsinflow of a second fluid and has a rectangular cross section; a valvebody being provided in a freely rotatable manner in the valve seat ofthe valve main body so as to simultaneously switch the first valve portfrom an closed state to an opened state and switch the second valve portfrom an opened state to a closed state, the valve body being formed intoa half-cylindrical shape having a predetermined central angle and beingformed into a curved-surface shape or a planar shape at each of both endsurfaces of the valve body in a circumferential direction; and drivemeans configured to drive the valve body to rotate.